Late spring in A pennsylvania garden means lots of insects, from silk tents in cherry trees to woolly bears on the move. There’s a lot of wildlife in there, but it can be hard to notice till things gets damaged. When your tomato plants turn skeletal, you need identification: Which one is it? The chart above show most common species (by host plant and other visual clues) statewide.
In fact not all caterpillars hurt us in the garden, or even signify trouble. Some mean healthy soil, and others will eventualy become beneficial pollinators. Wooly bears aren’t bad. Monarchs only eats milkweed, storing their protective poisons with it. Black swallowtails might chew up some parsley but eventually pollinate flowers as butterflies. Managing the garden is easier if you know whom to tolerate, right?
How to Identify and Manage Garden Caterpillars
First you have to find out where they’re hiding, and then. Daytime searches for caterpillars are what most of us do. This is often not good, as so many pests is nighttime feeders. By morning they’re tucked back up under leaves or in the ground. A dusk search with a flashlight reveals far more insects we’d missed in the daylight. Hornworms show themselves then, right around the stems and you’ll spot their poop. Far better to hunt for the poop than for the worm itself. Even when the worm’s gone, you can still see the evidence. Adjusting the schedule help big-time on detecting rates.
The infographic highlights certain characteristics to focus on visually: Color is important; so is body texture. Moth bodies tend to be covered with a lot of hairs; hornworms’ and swallowtail’s are smooth. Some of those hairs aren’t harmless. The saddleback caterpillar (above) looks harmless enough. Small and green, but it sports venomous spines on its sides that cause painful burning and swelling immediate upon contact. Assume all unfamiliar hairy larvae will sting you, just in case. That way you would of not have any unpleasant surprises down the road.
Knowing the right pest to look out for depends off the season. For instance, eastern tent caterpillars sets up shop in April, making their silken webs in tree forks. Then tomato hornworms reach their peak in July-August, when weather’s hot enough to promote quick growth. In fall, the webworms makes their silk mats on branch ends (mostly an eyesore issue). All those creatures have a rhythm that matches the plants’ cycle and the temperature. Knowing that calendar help you be proactive rather than reactive to damage.
If you get started early, there is no need for the harshest chemicals. Handpicking (try dusk) helps keep populations down, particularly in small garden. This does no harm to your friendly predator population. You can introduce biological controls such as parasitic wasps that target individual pests and do not bother other bugs. Use B.t. B.t. Sprays use the active ingredient bacillus thuringiensis, which kills very young larvae but degrades rapidy in sun. All these tactics help safeguard crops while maintaining the garden ecosystem.
Work with nature, not always against it. It’s not about eradicating all the caterpillars, but balancing them. It’s learning to read the clues on branches and leaves (what to leave alone and what to remove). It takes time, a few seasons of doing it, and then you’re discerning. A web in your apple tree? A striped larva on your dill? You’ll know. The closer you look, the more the garden shows itself to you.